Combined deployment technique
The entire combined procedure was performed in an electrophysiology laboratory, under sterile conditions and with the patient undergoing conscious sedation or local anesthesia. The first part of the S-ICD device system placement procedure was performed following the two-incision technique as first reported by Knops et al. 7. Device pocket was created inter-muscularly, carefully separating the anterior surface of the serratus anterior and the posterior surface of the latissimus dorsi muscle.
Before device deployment, an AAE was retrieved. To allow fitting of the S-ICD device, the envelope was processed as follows: first, the envelope was dipped in a sterile bath of 0.9% saline. Then, using a surgical scissor, both lateral edges of the envelope were cut, to increase the envelope width span. As per manufacturer indication, the envelope was flipped inside out. The S-ICD device was then inserted into the wet, flipped, opened envelope. Through manual compression, envelope adhesion to the S-ICD was maximized. Three surgical knots, two anchoring the envelope to itself and one attached to the catheter port of the S-ICD device, were put in place, to guarantee envelope stability and fixation. Device was then placed in the inter-muscular pocket and standard techniques to suture the pocket and the incision site were used. The steps used for envelope preparation and deployment are shown inFigure 2 . At the end of the procedure, fluoroscopy was used to assess final system positioning. As per manufacturer indication, a 2-views chest radiography was obtained in the first post-operative day. All procedures were performed in high-volume centers by expert proceduralists (M.B., C.L.G., G.B.F.), with an extensive experience with the S-ICD system placement as well as with AAE.